_The physico-teleological argument_ comes next under Kant’s criticism. This argument is based upon the inference that intelligent design found in nature implies an intelligent designer of nature. Kant replies as follows: Even granting that the world exhibits the design of beauty, goodness, and purpose in its construction, such a beautiful, good, and purposeful world would only prove the existence of an architect and not the existence of a creator. Kant points out, however, that this proof is the oldest, clearest, and the most popular; and he thinks it deserves to be treated with respect on that account. The wonder and magnificence of nature must free man from the oppression of any subtle argument against the significance of nature. Nevertheless Kant feels that this proof lacks intellectual cogency; for it is possible that nature is freely acting and has power within itself. The conclusion of the _Dialectic_, in which the Reason attempts through its Ideas to soar beyond experience, is that such speculation has never added to our knowledge. Mere conceptual thought cannot be knowledge of the reality of the soul, God, and the world. Still, the Ideas of the reason are an integral part of the human mind, and they must have their purpose. They cannot be verified by experience, in which alone is truth, but they can regulate experience. They are “regulative Ideas” in that our experience is better governed if we act as if there were a soul, as if God existed, and as if the world were a totality of related things. Moreover, while speculation cannot prove the existence of God, the immortality of the soul, and the freedom of the will, atheistic speculation is unable to prove the contrary of all these propositions. The Ideas of the Reason clear the way for faith based on morality.